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The Single UNIX &reg; Specification, Version 2<br>
Copyright &copy; 1997 The Open Group

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<h4><a name = "tag_000_008_480">&nbsp;</a>NAME</h4><blockquote>
setreuid - set real and effective user IDs
</blockquote><h4><a name = "tag_000_008_481">&nbsp;</a>SYNOPSIS</h4><blockquote>
<pre><code>

#include &lt;<a href="unistd.h.html">unistd.h</a>&gt;

int setreuid(uid_t <i>ruid</i>, uid_t <i>euid</i>);
</code>
</pre>
</blockquote><h4><a name = "tag_000_008_482">&nbsp;</a>DESCRIPTION</h4><blockquote>
The
<i>setreuid()</i>
function sets the real and effective user IDs of the current process to the
values specified by the <i>ruid</i> and <i>euid</i> arguments.  If <i>ruid</i> or
<i>euid</i> is -1, the corresponding effective or real user ID of
the current process is left unchanged.
<p>
A process with appropriate privileges can set either ID to any value.  An
unprivileged process can only set the effective user ID if the <i>euid</i>
argument is equal to either the real, effective, or saved user ID of the
process.
<p>
It is unspecified whether a process without appropriate privileges
is permitted to change the real user ID to match the current real, effective
or saved user ID of the process.
</blockquote><h4><a name = "tag_000_008_483">&nbsp;</a>RETURN VALUE</h4><blockquote>
Upon successful completion, 0 is returned.  Otherwise,
-1 is returned and <i>errno</i> is set to indicate the error.
</blockquote><h4><a name = "tag_000_008_484">&nbsp;</a>ERRORS</h4><blockquote>
The
<i>setreuid()</i>
function will fail if:
<dl compact>

<dt>[EINVAL]<dd>
The value of the <i>ruid</i> or <i>euid</i> argument is invalid or out-of-range.

<dt>[EPERM]<dd>
The current process does not have appropriate privileges, and either an attempt
was made to change the effective user ID to a value other than the real user
ID or the saved set-user-ID or an an attempt was made to change the real user
ID to a value not permitted by the implementation.

</dl>
</blockquote><h4><a name = "tag_000_008_485">&nbsp;</a>EXAMPLES</h4><blockquote>
None.
</blockquote><h4><a name = "tag_000_008_486">&nbsp;</a>APPLICATION USAGE</h4><blockquote>
None.
</blockquote><h4><a name = "tag_000_008_487">&nbsp;</a>FUTURE DIRECTIONS</h4><blockquote>
None.
</blockquote><h4><a name = "tag_000_008_488">&nbsp;</a>SEE ALSO</h4><blockquote>
<i><a href="getuid.html">getuid()</a></i>,
<i><a href="setuid.html">setuid()</a></i>,
<i><a href="unistd.h.html">&lt;unistd.h&gt;</a></i>.
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UNIX &reg; is a registered Trademark of The Open Group.<br>
Copyright &copy; 1997 The Open Group
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